Controlling attosecond electron dynamics by phase-stabilized polarization gating
Controlling attosecond electron dynamics by phase-stabilized polarization gating
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DOI：
10.1038/nphys281
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发表时间：
2006-05-01
期刊：
影响因子：
19.6
通讯作者：
Nisoli, M.
中科院分区：
文献类型：
--
作者：
Sola, I. J.;Mevel, E.;Nisoli, M.
当强激光场电离原子或分子时，产生阿秒电子波包（1）。当激光场驱动波包回到母离子时，它们与束缚波函数发生干涉，产生相干的亚飞秒极紫外光脉冲。当只有一个单一的返回是可能的（2，3），一个孤立的阿秒脉冲产生。在这里，我们证明，通过调制载波包络相位稳定的短激光脉冲（4）的偏振，我们可以精细地控制电子波包动力学。我们使用高次谐波产生探测这些动态。在优化的条件下，我们观察到一个单一的返回的电子波包在一个大的能量范围内的签名。这在时间上限制了极紫外辐射到具有宽的和可调谐的带宽的隔离的阿秒脉冲。我们的方法是非常普遍的，并扩展了阿秒隔离脉冲的带宽，以这样一种方式，几个阿秒的脉冲似乎是可以实现的。直接使用宽带电子波包也可以获得类似的时间分辨率。这为原子或分子波函数（5，6）和超快动力学的时间分辨层析成像开辟了一个新的领域。
Attosecond electron wavepackets are produced when an intense laser field ionizes an atom or a molecule(1). When the laser field drives the wavepackets back to the parent ion, they interfere with the bound wavefunction, producing coherent subfemtosecond extreme-ultraviolet light bursts. When only a single return is possible(2,3), an isolated attosecond pulse is generated. Here we demonstrate that by modulating the polarization of a carrier-envelope phase-stabilized short laser pulse(4), we can finely control the electron-wavepacket dynamics. We use high-order harmonic generation to probe these dynamics. Under optimized conditions, we observe the signature of a single return of the electron wavepacket over a large range of energies. This temporally confines the extreme-ultraviolet emission to an isolated attosecond pulse with a broad and tunable bandwidth. Our approach is very general, and extends the bandwidth of attosecond isolated pulses in such a way that pulses of a few attoseconds seem achievable. Similar temporal resolution could also be achieved by directly using the broadband electron wavepacket. This opens up a new regime for time-resolved tomography of atomic or molecular wavefunctions(5,6) and ultrafast dynamics.